In the art of elevator-type material conveyor systems, containers or so-called “buckets” are supported spaced-apart on an endless belt or chain for moving particulate material substantially vertically at least between a first elevation and a second higher elevation. A common application for elevator-type conveyor systems and the buckets associated therewith is for grain elevators as well as other applications wherein granular or particulate solid materials or material mixtures are conveyed by loading the buckets with conveyance material as the buckets move along the path of the endless belt or chain support structure. As the buckets go over the top of the conveyor, they tip over and empty, ready for more material on their way up again.
Material can fill the bucket by moving along a conveyor belt, falling off the end of the conveyor belt and into the bucket through an opening, typically located in the top of the bucket. The material that fills the bucket is abrasive and wears away the front edge lip and a forward portion of side walls of the bucket as it falls from the conveyor belt into the bucket. Also, not all material that falls off the conveyor belt is captured by the bucket. The buckets can be positioned to pick up the materials sitting on the ground that did not fall into the bucket. The materials scrape against the front edge lip and a forward portion of side walls of the bucket as the bucket picks them up from the ground and wear away the portion of the bucket that contacts the materials.
The buckets can be made from many types of materials, and material selection is typically based on cost, environmental factors, and the particular type of material being conveyed by the bucket. Elevator buckets are made of one material, and the material typically comprises polymers such as polyethylene, particularly high-density polyethylene (HDPE), polyurethane, and nylon.
A longstanding problem with elevator buckets relates to excessive wear on the front edge lip and a forward portion of side walls of the buckets incurred as the flow of material being conveyed filling the buckets while they pass along their path of movement. Premature failure of the front edge or lip can result in loss of bucket capacity which adversely affects material transport operations. Increasing material thickness uniformly throughout the bucket structure is disadvantageous from the standpoint of cost and the added tare weight of the buckets, for example. Buckets made from HDPE are cost effective but wear quickly. Buckets made from nylon or urethane polymer are very expensive but are much more abrasion resistant when compared to HPDE buckets and wear very slowly.
Accordingly, there has been a need to develop an elevator bucket which has an improved working life, is not subject to premature wear to the extent that the bucket will fail and will not likely undergo measurable, reduced capacity, while being only slightly more costly to produce than an elevator bucket made entirely of HDPE.